Questions tagged [supernova]

Questions regarding stars which increase suddenly in energy output due to an explosion which ejected much of its mass.

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What's the safe distance from a hypernova?

Hypernovae are even rarer than supernovae, occuring in stars at more than 30 solar masses, destroying the star that goes hypernova. This post states a hypernova releases several million times more ...
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Can a supernova or a close passing star create a transient sun gravity focus “habitable zone”?

This question was inspired by the previous question Would a black hole passing next to a star create a deadly focal point due to gravitational lensing?. I understand, as gravity also acts on light, ...
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Stellar life cycle flow chart with mass conditions and time scales

I remember that in my nuclear astrophysics lecture a decade ago, our lecturer drew a large flow chart like diagram of stellar evolution in dependence of the mass of the star (in solar units) on the ...
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Where did the hydrogen come from in a type II supernova?

Type II supernovae have hydrogen. Where did the hydrogen come from if that is the first element used up in the star's life cycle? Also if our solar system was seeded from an ancient supernova where ...
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How big would the supernova when a neutron star collides with another neutron star? [closed]

If two neutrons stars that are orbiting were to collide, how big would the supernova explosion be? Would a new black hole or a new supernova remnant be formed?
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How long does it take for a white dwarf to undergo a type Ia supernova?

I read about white dwarfs and their relation to Type Ia supernovae, and I want to know how much time passes between when the white dwarf passes the Chandrasekhar limit and when the white dwarf ...
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Type II supernovae as a distance indicator

Could someone explain in brief exactly how type II supernovae could be used as distance indicators? as in simply the formulae used and how they are employed? I know there are certain methods based on ...
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What is the “shockwave” of a supernova?

A common notion is that supernovae create shock waves in interstellar gas, and can compress them to star forming densities. How is that shockwave transmitted? Is it by ejected (sublight) particles, or ...
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How do you know that the remnants of the explosion of a Star are of a Hypernova?

Some Background? There are many types of Supernovae that can be classified into the following categories :- (This list is available here.) Type 1A supernovae • Their spectra show very little hydrogen ...
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How can many stars be formed from the remains of one supernova?

A supernova is the explosion of a single star; so how is it that thousands of stars can "be born of" that one explosion (presumably only using the unspent fuel / lighter elements of the ...
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How many supernovae events are on their way from within the Milky Way?

The Milky Way has a diameter of around 100.000 light years with the Solar system placed some 25,000 light years from the center. If we assume a supernova rate of 1 per century, and also assume that ...
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Calculating Relative Abundances to Solar For Explosive Nucleosynthesis Yields

I am having trouble deriving the abundance ratios for the ejecta products of a given supernova explosion model. From the explosion models, we are given the mass of 3 isotopes of every element produced ...
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Did I see a supernova explosion?

I think I just saw a supernova explode with my own eyes through my GSO 12 inch Dobsonian. Please tell me what it was! I am still trying to find what it was it was mindblowing! I went out on my roof ...
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Would a naked eye supernova become a disc in a matter of days?

Stars are points of light even in telescopes- if they go supernova, their diameter does expand, but given the distance of even nearby stars, they would still be points of light, I suppose? I am asking ...
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What does “located in the Hubble flow” mean?

I do not understand that much about the term Hubble flow. For cosmological studies with type Ia supernova, I often see the sentence like "We used 100 SNe Ia in the Hubble flow". What does ...
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Why did supernova 1987A's “String of 'Cosmic Pearls'” appear to be so lumpy 20 years later? Is it still?

NASA's A String of 'Cosmic Pearls' surrounds an exploding star is beautiful and the page says: This image shows the entire region around the supernova. The most prominent feature in the image is a ...
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How can I estimate the initial luminosity of a SNIa given initial mass of Ni-56?

The initial portion (and peak) of a SNIa's light curve is powered by the $\beta$-decay reaction: $$ ^{56}Ni \rightarrow ^{56}Co + e^+ + \nu_e + \gamma $$ Supposing we know how much Ni-56 is created in ...
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At what distance could a supernova damage the Earth's ozone layer?

As from my latter question it seems Betelgeuse might be much closer than the usually presumed 640 light years. It might be as close as ~440 ly. Suppose it is, would this have any dangerous effects on ...
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Galactic winds/outflows: why and how are they detected via blueshifted absorption lines in spectra?

I know that galaxies can eject gas due to supernovae, accreting black holes, etc. These galactic "winds/outflows" are often defined/detected observationally using blueshifted absorption ...
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When was it worked out/discovered that our sun can't go supernova?

As the title says, when did we realise with reasonable confidence that our star is not going to be going out in a supernova blaze of glory? I ask because a while ago I read The Songs of Distant Earth ...
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What happens when a huge star is being consumed by a black hole

What happens when a huge star in its later stage( iron core) is near a black hole that slowly consumes some of the matter from the star? Would this offset the imbalance caused by iron fusion ...
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Why are there so few supernovae in M31 (Andromeda)?

Estimates of the supernova rate in the Milky Way put it at a few per century, but very few of these are visible from Earth (at least with the naked eye) because of intervening gas and dust clouds). On ...
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How often are supernovas visible by the naked eye from Earth?

I heard about the 1054 supernova that was visible with the naked eye. Of course, these events happen at random. But just like with radioactive decay, it must be possible to determine statistics on ...
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any proof that stars are born, and die?

I've heard from a lot of people that stars are "born" (usually from black holes), then grow bigger, then eventually "die" by some kind of supernova etc., but have any of these events actually been ...
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What kind of radiation do supernova remnants emit?

Do supernova remnants emit EM radiation? Moreover can neutrinos be emitted by these remnants?
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Why do pair production and photodisintegration have such different effects in collapsing supermassive stars?

Stars of at least 100 solar masses or so can reach core temperatures (and, thus, core photon energies) great enough that pair production (where a very-high-energy photon strikes another particle, ...
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Why don’t supergiants at least start to fuse nickel into even heavier elements before going supernova?

The last primary fusion process to take place in extremely massive stars is silicon burning, where the 28Si produced by oxygen burning is exothermically fused with alpha particle after alpha particle ...
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How to derive the formula of magnitude error caused by peculiar velocity?

I want to understand how to derive the formula of magnitude error ($\sigma_m$) which is caused by peculiar velocity of a galaxy, like this $$ \sigma_m = \frac{5\ \sigma_V}{cz\ \rm{ln(10)}} $$ ,where $\...
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Was the “green star” event in NGC 3314 ever figured out or named?

from NGC 3314 Variable Object by By Bill Keel (University of Alabama, Tuscaloosa) and Lisa Frattare (Hubble Heritage Project, STScI). The object in question is circled. Comments below this answer led ...
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What causes fast moving pulsars to move so fast?

This article investigates the traces left in the ISM by fast moving pulsars. Is there a mechanism specific to pulsars that causes them to move so fast, or are there just as many fast moving stars? ...
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Do all High-Mass X-Ray Binaries have observable supernova remnants surrounding them?

I am studying high mass X-ray binaries, which are star systems that generally contain a neutron Star orbiting a larger companion. My assumption is that such systems began as two typical stars in ...
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How does a supernova occur when a massive star collapses into a black hole?

My layman's understanding of a supernova explosion is that it's caused by a rebound when a massive star collapses. When the core collapses to a point where neutron degeneracy pressure dominates, the ...
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When Betelgeuse goes supernova, will the explosion hit any neighboring stars?

There is evidence Betelgeuse might go supernova "soon". Are there any stars in the vicinity of Betelgeuse that are close enough that they will be hit by the explosion of this supernova? What would be ...
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How scientists estimated the number of near-Earth supernovae over the last 11 million years?

According to this article on wikipedia, An estimated 20 supernova explosions have happened within 300 pc of the Earth over ...
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Have we ever seen the formation of a blackhole?

So I know that the formation of a supernova has been observed and that we have taken images of blackholes, however, has the formation of a blackhole ever been observed. How do we observe it?
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How many galaxies have had their distance determined using SNIa?

Supernovae of type Ia can be used as standard candles to determine extra-galactic distances. But these event only occur (roughly) once every 200 years in any given galaxy and rapidly fade away. So to ...
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How often do supernovae occur?

Type Ia supernova are used as standard candles. But they also are transient events. This means that to determine the distance of a galaxy using supernovae, you have to wait for one to occur. How often ...
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Will the nebula of Betelgeuse be visible to the naked eye? How bright, how large, how soon, for how long?

When Betelgeuse goes core collapse supernova it will leave a supernova remnant. Will it become visible to the naked eye? If so, in what time frame will it be visible. Will it be star like from the ...
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Are stars expected to become dimmer before a supernova?

With the recent news about the "fainting" of Betelgeuse and the speculation that this might be a precursor to a supernova, I'm wondering if there is any theoretical/observational basis for this ...
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What would the effects on or around Earth if Betelgeuse went supernova?

There's been a lot of news lately about Betelgeuse possibly exploding sooner than perhaps was expected. Some examples: Guinan, Edward F.; Wasatonic, Richard J.; Calderwood, Thomas J. (8 December 2019)...
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What observation can be expected on LIGO if any when Betelgeuse goes supernova?

What observation can be expected from the LIGO† gravitational wave observatory if any when Betelgeuse goes supernova? Could we know that Betelgeuse has gone supernova before we see it light up our ...
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Why does the Supernova 2006cm give a very different value for the Hubble constant? Why doesn't it increase error bars for the Hubble constant?

The Supernova 2006cm has a redshift of 0.0153 which translates into a recession speed of 4600 km/s. It has a distance modulus of 34.71 which translates into a luminosity distance of 87 Mpc. This ...
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Element Abundance Related To Star Explosions [closed]

Sorry if this question is too basic, but as I learned about how supernovae are means of producing heavy elements I began to wonder "What would happen if stars didn't explode, i.e. undergo supernova"? ...
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Proxima as Supernova

Follow this question. If a star at the same distance from us as, say, Proxima Centauri had exploded as a Supernova 4 years ago (I know, it can't explode as supernova, let's say it can)... How bright ...
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Why do we expect Type Ia Supernovae to be brighter in a decelerating Universe than what has been observed?

This seminal review paper in the PNAS by Robert P. Kirshner (https://www.pnas.org/content/96/8/4224) says the following: If the universe had been decelerating—–in the way it would if it contained ...
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What kind of star would allow for life like our Sun/Earth and then go nova?

In the Star Trek Prime Universe, Star Trek: The Original Series, the home stars of the Fabrini, Platoans and Sarpeidons went nova, while in Star Trek: The Next Generation one of the stars in the ...
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Is the resulting light from a supernova a product of photons bouncing around in the Sun?

I was thinking about how photons formed in the centre of the Sun take quite a long time to exit the surface. And it occurred to me that at the end of a star's life (during a supernova, given that it's ...
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What do the fusing 'onion layers' of a pre-supernova star look like to scale?

I'm sure we've all seen the diagrams of various layers of element fusion from hydrogen to silicon in a star that's just about to go supernova. (Picture from courses.lumenlearning.com) I suspect ...
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Why does matter stay collapsed in the core, following a supernova explosion?

Following a supernova explosion a star may turn into a white dwarf, neutron star, black hole, or just a stellar dust & gas leftover. Excluding the latter case, why and how does the star's core ...
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Estimating the abundance of type-Ia supernovae using magnitude limited survey

I would like to estimate the fraction of type-Ia supernovae in a magnitude limited survey (only including those supernovae that are brighter than a certain than a given fixed apparent magnitude). I ...